Heat exchange apparatus



March 19, 1935. D. R. McNEAL HEAT EXCHANGE APPARATUS Filed April 16,1932 a/fifl INVENTOR.

,', .1 v ATTORNEYS.

Patented Mar. 19, 1935 UNITED STATES PATENT OFFICE 1,994,779 .nEA'rEXCHANGE APPARATUS Application April 16,1932, Serial No. 605,619

7 Claims.

This invention relates to heat exchange apparatus and is especiallyconcerned with a relatively simple and inexpensive small exchangerparticularly suitable for cooling air or other gases.

.5 In considering some of the objects of the invention, it should firstbe noted that in a great variety and a large number of instances, it isdesirable to employ a relatively small size heat exchange device,preferably connected directly into a gas or air supply line, it beingnoted that for many purposes it is highly desirable that the exchangeremployed be of the straight-line or direct connection type. That is, forexample, in an air supply line extended from a pressure reservoir tosome point of use, it is desirable to employ a small size exchanger(usually a cooler) and at the same time maintain direct or straight-linecommunication through the air line. Heretofore, in many cases where suchuse was apparent, the cooler desired could not be employed as apractical matter, either because of the complication of apparatusheretofore provided for the purpose, or because of the relatively greatexpense which the cooler necessitated in installation and maintenance.

It is with apparatus adapted to overcome the foregoing difficulties anddisadvantages that the present invention is concerned. An object of thisinvention, therefore, is to provide a relatively g inexpensive andsimple heat exchange device especially adapted for direct connection inan air or gas supply line, particularly for the purpose of cooling theair or gas.

The invention also contemplates a cooler which maintains straight-lineor direct communication through the supply line.

A still further object of the invention resides in the arrangement ofthe cooler parts, or at least a major portion thereof, in such mannerthat they may readily and conveniently be formed of standard tubingstock and the like.

The manner in which the foregoing objects and advantages are attained,together with others which will occur to those skilled in the art, willbe more apparent from a consideration of the following descriptionmaking reference to the accompanying drawing, in which Figure 1 is alongitudinal sectional view through a heat exchange device constructedin tially as indicated by the section line 1-1 on Figure 2;

Figure 2 is a sectional view taken substantially as indicated by thesection line 2-2 on Figure 1; and

accordance with this invention, taken substan- Figure 3 is a fragmentarysectional view of one end of a modified exchanger device.

Referring first to the showing of Figures 1 and 2, the gas or air linewith which the exchanger is to be associated is indicated as beingbroken and provided with opposed end portions 4 and 5. The various partsof each end of the device are entirely similar to those employed at theopposite end so that a description of one and only need be considered.It should be borne in mind in connection with this fact, however, thatit is of advantage in a simplified and inexpensive heat exchange deviceto employ as many duplicate parts as possible since this materiallyreduces expense in manufacture, repair, etc.

Referring then specifically to the parts of the device shown at the leftof Figure 1, it will be seen that the pipe connection 4 is threaded intoa cylindrical part 6 formed integrally with a base or disc 7 whichconstitutes a tube sheet. This part may conveniently and readily bemachined, as by drilling and the like, from standard bar material, itbeing noted that the cooler sizes to which this invention is especiallyadapted vary from approximately one to six inches in overall diameter.

A nest of relatively small diameter tubes 8 terminate in the sheet 1 andcommunicate with the interior of the cylindrical portion 6, thiscylindrical portion thus constituting a header for communication betweenthe pipe 4 and the tubes 8. Surrounding the tubes 8 I have provided atubular shell or casing 9 which may conveniently be cut from standard orstock tubing, and at each end, the header device 6-7 fits into the shellso as to provide a chamber surrounding the tubes in which a heattransfer medium may be circulated.

A cylindrical or annular member 10 is applied externally of the tube 9at each end thereof, it being noted that this part may also be cut fromstock tubing and welded, brazed or soldered in place as indicated by thereference numeral 11. This collar or annular member performs three majorfunctions. In the first place it serves to reenforce the end of thecasing 9. Secondly, it provides suflicient depth or thickness ofmaterial for a threaded connection 12 with which a pipe 13 for the heattransfer medium cooperates. The shell 9, of course, is also apertured,as at 14, in alignment with the threaded aperture 12 to provide forcommunication with the interior of the casing.

To perform its third major function, the collar 10 is preferablyextended outwardly beyond the end of the tube 9 in order to cooperatewith the cylindrical portion of the header device to form an annularpacking groove or chamber therebetween. Packing material or a packingring 15 is illustrated in Figure 1 as occupy this cavity, and a gland ortightening device 16 is provided for the purpose of maintaining thejoint tight. The gland may be drawn up by means of bolts 17 taking intolugs 18 attached to collar 10. The bolts 17 -also cooperate with thewings or ears 19 formed on the gland 16.

In order to provide a more or less extended path of travel of thecooling medium through the shell 9, I preferably employ baille devicesindicated at 2'7 in Figure 1, these baflies being arranged generallycross sectionally of the casing 9 at spaced points therealong, andfurther being alternately disposed to extend from opposite sides of thecasing and thus provide passages 28 around which the cooling medium mayflow as indicated by the arrow in Figure l. Spacing sleeves 27a may beemployed to position the several bailies lengthwise of the cooler. Thedirection of flow of the cooling medium through the casing 9 ispreferably generally reverse to the direction of air or gas flow throughthe cooling tubes 8. It is observed in this connection that theconstruction of the parts at opposite ends of the unit as counterparts,permits use thereof for air and cooling medium flow in either direction.

In the preferred arrangement, the cylindrical part 6 of the header meansis flattened as indicated at 20 to facilitate assembly or the like bythe use of a wrench, and in order to prevent relative rotation of thecasing 9 and the tubes with their associated header means, the headersmay be recessed as at 21 to receive a locking pin 22 convenientlythreaded into the collar 10.

In the modification of Figure 3, the tubes 8 and their surrounding shell9 remain exactly the same as in Figures 1 and 2. The packing or glanddevice 1511 and 16a also remains substantially the same in its relationto the casing 9, the collar 10a and the tube header device. In thisinstance, however, the cylindrical portion 6a of the header device isexternally threaded adjacent its outer end to receive an internallythreaded collar 23, and the tube or air line connection 5a is threadedinto an end plate 24. The plate 24, in turn, is secured to the outer endof the header part 6a, preferably with packing 25 interposedtherebetween. For the purpose ofattaching the plate 24, I employ bolts26 extended through apertures therein and threaded into the plate ordisc 23.

In considering some of the advantages of both forms of the inventionillustrated, it is first to be noted that the tube element, includingthe tubes themselves and their associated header means, constitutes asingle unit which is readily inserted or removed for purposes of initialinstallation or subsequent cleaning or repair. In accordance with Figure1 it is necessary only to loosen the bolts 17, displace the gland 16 bysliding it over the associated pipe connection, and then similarlydisplace the sleeve or tube 9 in order completely to expose the tubes 8.If desired, of course, the pipe connections 4 and 5 may then beuncoupled and the entire unit is open to inspection, cleaning or repair.A similar but reversed procedure, of course, is followed in initiallyassembling'or re-assembling the several parts.

In accordance with the arrangement of Figure 3 the parts may readily bedisconnected or taken down first by releasing bolts 26 and thenunscrewing the ring 23. After removal of the ring 23, the casing 9 maythen he slid off the end of the tube unit to gain access to any partswhich may require cleaning or repair.

The showing of Figure 3 illustrates the manner in which a flanged pipeconnection may be used to connect the cooler into an air or gas line.

One factor of major importance in attaining the objects and advantageshereinbefore referred to is involved in the arrangement of the heater insuch manner that the air or gas to be cooled is passed through thestraight-line tubes, the cooling medium being circulated between andaround the tubes within the casing 9. Bearing in mind the fact thatwater or some other suitable liquid is ordinarily employed for coolingpurposes, it will be seen that the foregoing arrangement does notnecessitate the use of glands or slidably packed joints at points wherethey will be subjected to air or gas pressure. The only slidable jointwhich'need be provided with a gland or packing device is interposedbetween the header means for the tubes and the casing 9. Thearrangement, therefore, is especially adapted to the cooling of air orgas by a liquid such as water, since the sliding joints between the twoheaders and thecasing 9 are subjected to water pressure only.Ordinarily, the water pressure need not be very high and, in any event,a joint of the character referred to may be much more efliciently packedas against leakage of a liquid than as against leakage of a gas.

The tubular formation of the several parts of .the device also permitsuse thereof even where air or gas under very high pressure is to becooled. Further in this connection, the passage of the air to be cooledthrough the tubes rather than around them is desirable in reducingvibrations,

and consequent wear, which heretofore has resulted where the materialbeing cooled is pulsating, as when it is delivered from a compressor.Certain features of such an arrangement, however, are not broadlyclaimed herein since they form a part of the copending application of D.Raymond McNeal, Serial No. 605,618, filed April 16th, 1932. Thesefeatures, however, are or" especial advantage in a small size heatexchangerof the character to which this invention relates since theyserve to further reduce the maintenance and replacement costs, it beingborne in mind that heretofore such costs have prohibited the use ofcoolers or the like in many instances where they should be employed foremcient operation.

With further reference to the advantages of the present construction,attention is called to the fact that the operation of an air compressornormally results in a very substantial increase in the temperature ofthe air compressed. The temperature, indeed, may often reach values ashigh as 300 to 400 Fahrenheit. Compressor operation also results in theformation of oil and water vapor and this is carried with the air-as itis discharged, usually to a receiver or storage tank. Under certainvapor, pressure and temperature conditions, a very highly explosivemixture is produced and this has not infrequently caused seriousexplosions, as a result of which heavy damage and injuries have beenincurred.

It will be seen from the foregoing that it is use. However, inaccordance with the practice of the prior art, even where attempts weremade to employ coolers in relatively small installations, such coolerscould not be located closely adiacent tothe compressor on account of theexcessive wear which resulted from the vibrations set up by thepulsations in the air discharged from the compressor.

This invention, however, in providing a cooler which is not subject tomaterial wear as a result of air pulsations, and which further serves toreduce the magnitude of the pulsations, particularly bearing in mind thefact that the several parts of the cooler may be manufactured veryinexpensively, makes it possible to employ a small size cooler disposedclosely adjacent to an air compressor. The advantages of such anarrangement should be fully apparent from the foregoing comments.

In conclusion, attention is again directed to the fact that at least amajor portion of the parts employed, in either embodiment of theinvention, may conveniently and efliciently be cut, drilled or machinedfrom stock tubing, sheeting and the like. In accordance with thisinvention, therefore, I have provided a heat exchange device especiallysuitable for small size installations such as are required, in manyinstances, for efiicient operation of air or gas supply lines.

I claim:

1. In combination with a substantially straight section of a fluidsupply line, a. heat exchange device interposed in said section, saiddevice ineluding a nest of tubes, tube supporting means at the endsthereof having means of connection into said section, a tubular shellsurrounding said tubes, said shell and the tube supporting means beingso relatively proportioned with respect to each other and with respectto the diameter of the fluid supply line as to permit uncovering of thetubes by sliding the shell over the tube supporting means at one endthereof to telescope with an adjacent portion of the Supp y line, to-

gether with means associated with said shell for circulating a heatexchange medium therein.

2; Heat exchange apparatus of the character described including incombination with opposed ends of a pipe line, header devices associatedwith the pipe ends, a plurality of tubes extended between the headerdevices to complete a substantially straight-line communication throughsaid line, and a shell surrounding said tubes between said devices andcooperating with the latter to provide a chamber for a heat exchangemedium, the shell being slidable endwise over a header device andassociated pipe end to expose the tubes.

3. In heat transfer apparatus of the character described, a tubularshell, a nest of tubes in the shell, tube supporting means at one end ofthe shell having a disc-like portion constituting a tube sheet and acylindrical portion, a member surrounding the shell and extended beyondthe end thereof to provide a packing chamber at the end of the shellbetween said cylindrical portion and said member, and a packing elementin said chamber.

4. In combination with an air line or pipe having threaded connectionmeans, an elongated sub- V 3 stantially straight-line air cooling deviceadapted to be connected with said line in substantial alignmenttherewith, said device including a tubular shell, a plurality ofrelatively small diameter tubes extended lengthwise through the shell,means for circulating a cooling medium through the shell around saidtubes, and a device fitting in said shell and having a substantiallycircular portion and a portion of cylindrical shape the latter of whichis substantially regular as to its cylindrical shape throughout anextended length thereof, the circular portion being arranged to serve asa tube sheet, the cylindrical portion being open at an end thereof andfurther being threaded on its substantially regular cylindrical wall tocooperate with the pipe connection means, and the said device and theshell being so proportioned as to provide for axial displacement of theshell over said device.

5. In combination with an air line or pipe having an externally threadedend, an elongated substantially straight-line air cooling device adaptedto be connected with said line in substantial alignment therewith, saiddevice including a tubular shell, a plurality of relatively smalldiameter tubes extended lengthwise through the shell, means forcirculating a cooling medium through the shell around said tubes, and amember fitting in said shell and having a substantially circular portionand a substantially cylindrical portion the latter of which issubstantially regular as to its cylindrical shape throughout the lengththereof, the circular portion being arranged to serve as a tube sheet,and the cylindrical portion being open at an end thereof and furtherbeing internally'threaded on its substantially regular cylindrical wallto cooperate with said externally threaded pipe end, and the cylindricalportion of said member and the said shell further being so proportionedas to provide for axial displacement of the shell over said member andthe connected pipe end to expose the tubes.

6. Heat exchange apparatus of the character described including a pairof header devices each having means of connection with a pipe, aplurality of tubes extended between the header devices, at least one ofthe header devices having a cylindrical outside wall, a shellsurrounding said tubes between said devices, the shell being formed ofstandard tubing stock of inside diameter such as to receive thecylindrical header, and a cylindrical member surrounding an end of theshell, the cylindrical member also being formed of standard tubing stockand projecting beyond an end of the shell to cooperate with thecylindrical wall of the header in forming an annular packing cavity atthe end of the shell.

7. A heat transfer device including a nest of tubes, a cylindrical shellsurrounding the tubes, a cylindrical member amending the shell adia'centan end thereof and secured thereto to reinforce the shell, saidcylindrical member and the shell being apertured to provide an openingfor the passage of a heat transfer medium and the aperture in the memberbeing threaded for connection with a pipe for said medium, whereby thecylindrical member serves as the means for connection with the pipe andalso as a reinforcement for the shell. P

D. RAYMOND McNEAL.

